A memory device has been proposed in which memory cells are three-dimensionally arranged by making memory holes in a stacked body in which multiple insulating layers are alternately stacked with multiple electrode layers that function as control gates of the memory cells, forming a charge storage film on the side walls of the memory holes, and subsequently providing silicon used to form a channel inside the memory holes.
Further, in such a memory device, a memory string structure having a U-shaped configuration has been proposed in which the memory string includes a pair of columnar portions extending in the stacking direction of the stacked body, which includes multiple layers of the electrode layers, and a linking portion that is buried in the back gate to link the pair of columnar portions.